Operational constraints are limitations on a vehicle's current or predicted status or performance. Non-limiting examples of operational constraints include maximum altitude, maximum speed, turning radius, approach angle, stopping distance, and the like. In the context of aircraft, operational constraints may affect fuel consumption, altitude, ground speed, and the like. Flight operations increase in complexity as the number of operational constraints increases. Part of the complexity is that each operational constraint may have a temporal relevance. Further, each operational constraint may comprise a plurality of parametric constraints, and each of those parametric constraints may influence a different aircraft subsystem, possibly at a different time. Further still, as operational environments become more complex, the amount of associated operational constraints governing operational efficiency and safety is also expanding.
Pilots receive information regarding the anticipated operational environment through various sources. One source of operational constraints, such as vehicle capabilities, is the minimum equipment list (MEL). Often, a pilot is handed a paper copy of a MEL and briefed on the operational constraints prior to starting a flight operation. After the briefing, the pilot must recall the respective parametric constraints and vehicle capabilities, consider relevant environmental data, associate the parametric constraints with a respective subsystem, and make the association at the appropriate time/location along a flight plan in order to make appropriate vehicle decisions. Any untimely recall of parametric constraints may lead to reduced anticipation time and unexpected aircraft performance. Consequently, this process represents a high cognitive workload for the pilot.
Accordingly, a vehicle decision support system capable of processing operational constraints, a flight plan, and appropriate environmental data to generate timely and readily comprehensible guidance is desirable. The desired decision support system improves the incorporation of operational constraints in a flight operation, as well as the timeliness and accuracy of their incorporation. The desired decision support system thereby improves overall aircraft safety.